Before “Back to Sleep”: Deformational plagiocephaly and pediatric insights from Iron Age Italy

Objective: Investigate whether deformational plagiocephaly, a common pediatric cranial condition, often linked to limited infant head mobility, occurred in an ancient population and its implications for infant care practices. Materials: Twenty-six Early Iron Age adult crania from Matelica, Italy (mid-9th–8th c. BCE). Methods: All crania underwent macroscopic assessment. Computed tomography was performed on those with posterior cranial asymmetry (n = 11) to support differential diagnosis. Severity was classified using the oblique cranial length ratio from standardized vertex images. Results: Eleven crania (42.3%) showed posterior asymmetry, with a male predominance (63.6%) and more common right-sided flattening (72.7%). Differential diagnosis excluded post-depositional changes, intentional modification, and craniosynostosis. In several cases, CT revealed occipital base flattening with ipsilateral mastoid anterior displacement - features vertex-based oblique cranial length ratio may underestimate. Seven individuals exhibited postcranial markers possibly consistent with congenital muscular torticollis, a condition clinically correlated with deformational plagiocephaly. Conclusions: The pattern is consistent with prolonged infant head immobility, plausibly linked to caregiving behaviors. Significance: These represent the earliest known Italian examples of deformational plagiocephaly, placing the condition in deep historical and evolutionary context. These findings suggest that deformational plagiocephaly may not be solely modern, supporting its interpretation as both a pediatric condition and cultural marker. Limitations: The small sample size and preservation-dependent skeletal markers limit interpretations. Infant care practices are inferred indirectly; oblique cranial length ratio may underestimate basal deformity. Suggestions for further research: Future comparative studies are needed to determine whether the high deformational plagiocephaly prevalence at Matelica is localized or represents a broader Iron Age pattern in central Italy.